Cardiac embryology

Question 1

Where is the cardiogenic region?

Answer 1

Visceral layer of the lateral plate mesoderm

Question 2

What do the angiogenic clusters form?

Answer 2

Endocardial tubes and dorsal aortae

Question 3

What does lateral folding do to the heart?

Answer 3

Bring endocardial tubes together to form single heart tube

Question 4

What does longitudinal folding do to the heart?

Answer 4

Moves endocardial tubes to thoracic region (dorsal to pericardial cavity)

Also fuses the dorsal aortae ventrally

Question 5

What does the bulbis cordis become?

Answer 5

1. Right ventricle
2. Conus cordis (root of aorta)
3. Truncas arteriosus (pulm trunk)

Question 6

What is the aortico-pulmonary septum? What defect occurs when it fails to form

Answer 6

Septum of the truncas arteriosus makes divsion between aorta and pulmonary trunk

Tetraology of fallot: Ventricular septal defect, Pulmonary stenosis, RV hypertrophy, Over-riding aorta

Question 7

What three veins drain into the sinus venosus?

Answer 7

1. cardinal veins (all over body)
2. vitelline veins (blookd from yolk sac)
3. umbilical veins (oxygenated blood from placenta)

Question 8

What do the vitelline veins become

Answer 8

Ductas venosus

Question 9

What do the right and left horns of the sinus veonsus become?

Answer 9

Right: expands to IVC, SVC, and atrial wall

Left: coronary sinus at AV groove

Question 10

What is the cristae terminalis?

Answer 10

separates smooth and rough muscle of RA

Question 11

Where does the smooth muscle of RA come from? Rough muscle?

Answer 11

smooth: veins (sinus venosus and pulmonary vein)
rough: primitive atrium

Question 12

What becomes the auricles?

Answer 12

Primitive atrial wall

Question 13

What fuses to become the 1st aortic arch?

Answer 13

truncas arteriosus and dorsal aortae

Question 14

What does the 4th aortic arch become in asymmetric remodeling?

Answer 14

Right: right subclavian artery

Left: aortic arch

Question 15

What does the 6th aortic arch become in asymmetric remodeling?

Answer 15

Right: disappears

Left: Ductas arteriosus

Proximal: Pulmonary arteries

Question 16

Where do the lymphatic come from?

Answer 16

Endothelium of the veins

Question 17

What are the three shunts in fetal circulation and what do they connect?

Answer 17

1. foramen ovale from atrial separation: connect two atria
2. ductus arteriosus from left 6th aortic arch: connect pulm trunk with descending aorta
3. ductus venosus from vitelline veins: bypass the liver

Question 18

What do the fetal shunts become at birth?

Answer 18

1. foramen ovale -> fossa ovalis
2. ductus arteriosus -> ligamentum arteriosum
3. ductus venosus -> ligamentum venosum

Question 19

Where does the membranous septum of the endocardial cushion come from?

Answer 19

Neural crest cells

Question 20

Where does the right pumonary artery travel? Left pulmonary artery?

Answer 20

Left: anterior to aorta

Right: posterior to aorta and SVC